The present invention relates to an apparatus for cutting to size and bending leads of electrical components, with the apparatus having transport toothed wheels for taking up leads between their teeth and bending toothed wheels, all such wheels being keyed on a driving main shaft supported by bearings in a support structure, cutting tools designed for use with the transport toothed wheels, bending tools designed for use with the bending toothed wheels, gripping toothed wheels elastically forced against the bending toothed wheels and meshing therewith, and with a further shaft, parallel to said main shaft, for supporting said gripping toothed wheels.
An apparatus is normally used for operations on the leads of electrical components such as resistors, capacitors, and diodes which, as a rule, but not necessarily, have two lead wires at opposite ends of the component and are normally in line with each other and with the axis of the component. Such components may or may not be connected together by belts of adhesive tape. Generally, such components come from the manufacturer in a form, in which the user is not readily able to put them directly into the circuit: The leads are generally more or less straight and, as a rule, are very much longer than needed for use in the circuit. For this reason, they have to be cut down to size and bent. Furthermore, for use in printed circuit boards or the like, such components have to be kinked so as to have a sort of "feet" with which they may be kept in the holes in a circuit board safely till soldering takes place. The designs of the bends and of the kinks do not have to be detailed here.
In a prior apparatus of the aforementioned type such as, for example, see German Pat. No. 2,030,818, British Pat. No. 1,414,234 and U.S. Pat. No. 3,900,053, the cutting to length and bending of the leads, and, possibly, if needed, kinking, takes place at a very high throughput rate as if it were only a question of a single working step.
In this respect the components, supported in the tooth spaces of toothed wheels placed coaxially in line, are moved past the tools for being cut to length, bent, and, if necessary, kinked. In this respect normally, for each lead wire, a complete toothed wheel group with transport, bending and, if necessary, kinking toothed wheels is present, which are used with stationary tools which, in a way dependent on their placing in the apparatus, take effect at different points in time, shortly one after the other, dependent in the way in which they are placed at the outer edges of the toothed wheels and their direction of turning.
To make certain that, when bending takes place, the body of the component is not acted upon by any pulling forces by which the leads might be pulled loose and the components damaged, the leads are gripped on bending between the position of bending and the body of the component. This is undertaken in apparatus of the sort in question by grippers in the form of toothed wheels, which, in the present invention, are named gripping toothed wheels and are naturally supported so as to be able to be freely turned so that they may be meshed with the bending toothed wheels. The wires are, in this respect because of the springing force acting on the gripping toothed wheels, gripped at the points of the teeth against the roots of the teeth of the bending toothed wheels. In the prior art apparatus, the gripping toothed wheels are supported by bearings on the said further shaft itself, which, for its part, is spaced from the main shaft in the housing. The spring system for acting on the gripping toothed wheels is, in this case, produced by a spring acting eccentrically on the further shaft.
This prior art apparatus of the sort in question will still be seen to have some shortcomings from different points of view. In general use in the trade, it is regularly necessary, on retooling for making different circuits with different components, not only for the toothed wheels, but furthermore the tools to be moved along the main shaft, dependent on the lengths coming into question, and then fixed in position. The adjustment of the toothed wheels is made possible because each wheel is joined to its own bush and the bushes may be pushed along the main shaft and being keyed to it. On retooling, the bending tools and the gripping toothed wheels have to undergo separate adjustment, this taking up much working time. Furthermore, because the gripping toothed wheels are supported by bearings on the further shaft as well, that is to say the shaft in addition to the main shaft, in the old apparatus, the gripping toothed wheels may not undergo adjustment separately to be in line with the lead with which the apparatus is to be used and, in fact, they are moved out of position to the same degree against the spring force. In trade use, however, it may be frequently the case that the leads of a component are differently curved or bent so that the gripping toothed wheels are moved out of position by the leads different amounts with the outcome that the other lead of a component is no longer positioned in the desired way.
Furthermore, for cutting to length, kinking and/or bending the wires of electrical components, further forms of apparatus of the general sort noted have been put forward (see German Pat. No. 2,256,290), using only a single shaft and, in place of gripping toothed wheels for use with the bending toothed wheels, finger-like grippers for limiting pulling forces on the component body are used which are springingly supported on the housing and come into play with the bending tools. In the case of this form of apparatus of a different sort, and which has been found to be more specially useful on processing thick leads, separate adjustment of the grippers and bending tools is necessary on retooling.